9 tourist attractions that are dying

(CNN)The dilemma is sometimes likened to a double-edged sword.

Historical and natural sites of extraordinary beauty often draw large numbers of visitors to the countries that host them, providing a healthy tourism revenue.
    However, those same crowds often have a detrimental effect on the places they visit, sometimes leading to significant damage, which has in recent years sparked a debate whether tourist numbers should be capped.
      "Sites all over the world are under threat at any given moment. Apart from the monuments and ancient cities in the Middle East, I would say historic districts of major cities in Asia face the highest threat due to the unchecked sprawl and development," says Stefaan Poortman, executive director of the Global Heritage Fund, whic